DESCRIPTION: Proposed is a study of what may be a novel set of properties for the E. coli RNA polymerase core protein genes (rpoA, B and C genes). These genes are known to be growth rate regulated, and that regulation occurs by several transcriptional and translational mechanisms, but the detailed mechanisms and their coordination are largely obscure. Our sequence analyses show that the 5' ends of these genes contain UUU-Ynn dicodons, which are known to be highly frameshift-prone, and which are strongly avoided in other highly expressed genes. That these UUU-Ynn sequences occur near the 5' ends of all three rpo genes, and that this pattern is shared by diverse bacteria, suggests that these sites may have undiscovered, important functions. We will determine whether these sequences are frameshift-prone and whether frameshifting can contribute to regulation of these genes. The rpoB gene may be especially interesting because it encodes a potential frameshift-polypeptide that would be large enough to have function. This feature is also conserved among diverse bacteria. We will determine whether expression of this polypeptide has any global effect on cell physiology, and whether it specifically affects rpo gene expression. These studies may uncover interesting phenomena in the regulation and expression of the physiologically important rpo genes. This work will also train undergraduates interested in biomedical careers.